The narrator of the story is Scout, whose real name is Jean Louise Finch.  She is a person going back in her youth because she starts by going on a retrospective view on what happened to her brother, and speaks at all points in a reflective manner, starting with her family history. Throughout the story you notice that she has undergone some major maturity change that came as a result of a situation which occured, in part, due to the personality traits of her father.

In the end you realize that she has been telling you a story about transformation: personal, psychological, societal, and spiritual almost, which she learned earlier in her life do to the events in the story.